Service provisioning in an optical network includes establishing a restoration connection when a fault in a link of an existing path occurs. Typically, in an optical network, when a fault in a link occurs, each connection along the original path is torn down and new connections are set up to reestablish the path. Setting up a connection in an optical network is more complicated than setting up a connection in a digital network. As an example, establishing a new connection in an optical network must allow for the additional time it takes to adjust an amplifier gain and to tune a laser to the proper wavelength at both the source and the destination node of the connection. For example, retuning a laser may take tens of seconds. The resultant delay can range from mere annoyance to the time-out of critical devices that were using the failed path.
Therefore, there is a need for establishing an alternate path when a link fails in an optical network in a manner that restores service as quickly as possible that does not require a change of laser wavelength or change in amplifier gain.